Workshop Manual

6E–328
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC)
P0446 EVAP Canister Vent Control Malfunction
060RY00398
Circuit Description
The evaporative system includes the following
components:
B Fuel tank
B EVAP canister vent solenoid
B Fuel tank (vapor) pressure sensor
B Fuel pipes and hoses
B Vapor lines
B Fuel cap
B Evaporative emissions canister
B Purge lines
B EVAP canister purge solenoid
An incorrect fuel tank pressure sensor signal is detected
by monitoring fuel tank pressure when the key is first
turned “ON” during a cold start. If the fuel tank pressure
signal is out of range, DTC P0446 will set. A restricted or
blocked EVAP vent path is detected by monitoring fuel
tank pressure during normal operation (EVAP canister
vent solenoid open, EVAP canister purge solenoid
normal). With the EVAP canister vent solenoid open,
vacuum level in the system should be very low unless the
vent path is blocked. A blockage can be caused by the
following condition:
B Faulty EVAP canister vent solenoid (stuck closed).
B Plugged, kinked or pinched vent hose.
B Shorted EVAP canister vent solenoid driver circuit.
B Plugged evaporative canister.
If any of these conditions are present, DTC P0446 will set.
Conditions for Setting the DTC
B No TP sensor, ECT sensor, Tank pressure sensor, IAT
sensor, or MAP sensor DTCs set.
B Start-up engine coolant temperature and start-up
intake air temperature are more than 4°C (39°F) but
less than 34°C(93°F).
B Start-up engine coolant temperature is not more than
7°C (13°F) greater than start-up intake air
temperature.
B Fuel tank level is between 15% and 85%.
B BARO is greater than 70 kPa.
Action Taken When the DTC Sets
B The PCM will ON the MIL after second trip with
detected the fault.
B The PCM will store conditions which were present
when the DTC set as Freeze Frame and Failure
Records data.
Conditions for Clearing the MIL/DTC
B The PCM will turn the MIL “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.
B A history DTC P0446 will clear after 40 consecutive
warm-up cycles have occurred without a fault.